Search Publications
Strong Far-infrared Cooling Lines, Peculiar CO Kinematics, and Possible Star-formation Suppression in Hickson Compact Group 57
Appleton, P. N.; Xu, C. K.; Charmandaris, V. +14 more
We present [C II] and [O I] observations from Herschel and CO(1-0) maps from the Combined Array for Research in Millimeter Astronomy (CARMA) of the Hickson compact group HCG 57, focusing on the galaxies HCG 57a and HCG 57d. HCG 57a has been previously shown to contain enhanced quantities of warm molecular hydrogen consistent with shock or turbulen…
Spectroscopic classification of icy satellites of Saturn II: Identification of terrain units on Rhea
Stephan, K.; Capaccioni, F.; Cerroni, P. +4 more
Rhea is the second largest icy satellites of Saturn and it is mainly composed of water ice. Its surface is characterized by a leading hemisphere slightly brighter than the trailing side. The main goal of this work is to identify homogeneous compositional units on Rhea by applying the Spectral Angle Mapper (SAM) classification technique to Rhea’s h…
Interaction between Two Coronal Mass Ejections in the 2013 May 22 Large Solar Energetic Particle Event
Li, Gang; Ding, Liu-Guan; Chen, Yao +7 more
We investigate the eruption and interaction of two coronal mass ejections (CMEs) during the large 2013 May 22 solar energetic particle event using multiple spacecraft observations. Two CMEs, having similar propagation directions, were found to erupt from two nearby active regions (ARs), AR11748 and AR11745, at ~08:48 UT and ~13:25 UT, respectively…
NuSTAR J033202-2746.8: Direct Constraints on the Compton Reflection in a Heavily Obscured Quasar at z ≈ 2
Harrison, F. A.; Stern, D.; Zhang, W. W. +25 more
We report Nuclear Spectroscopic Telescope Array (NuSTAR) observations of NuSTAR J033202-2746.8, a heavily obscured, radio-loud quasar detected in the Extended Chandra Deep Field-South, the deepest layer of the NuSTAR extragalactic survey (~400 ks, at its deepest). NuSTAR J033202-2746.8 is reliably detected by NuSTAR only at E > 8 keV and has a …
Confirmation of a High Magnetic Field in GRO J1008-57
Hailey, Charles J.; Chakrabarty, Deepto; Fürst, Felix +11 more
GRO J1008-57 is a high-mass X-ray binary for which several claims of a cyclotron resonance scattering feature near 80 keV have been reported. We use NuSTAR, Suzaku, and Swift data from its giant outburst of 2012 November to confirm the existence of the 80 keV feature and perform the most sensitive search to date for cyclotron scattering features a…
Conjugate observations of Saturn’s northern and southern H3+ aurorae
Baines, Kevin H.; O'Donoghue, James; Moore, Luke +7 more
We present an analysis of recent high spatial and spectral resolution ground-based infrared observations of H3+ obtained with the 10-m Keck II telescope in April 2011. We observed H3+ emission from Saturn’s northern and southern auroral regions, simultaneously, over the course of more than 2 h, obtaining spectral images along the central meridian …
Mapping the integrated Sachs-Wolfe effect
Dodelson, S.; Manzotti, A.
On large scales, the anisotropies in the cosmic microwave background (CMB) reflect not only the primordial density field but also the energy gain when photons traverse decaying gravitational potentials of large scale structure, what is called the integrated Sachs-Wolfe (ISW) effect. Decomposing the anisotropy signal into a primordial piece and an …
First direct observation of sputtered lunar oxygen
Barabash, S.; Holmström, M.; Futaana, Y. +5 more
We present the first direct measurement of neutral oxygen in the lunar exosphere, detected by the Chandrayaan-1 Energetic Neutral Analyzer (CENA). With the lunar surface consisting of about 60% of oxygen in number, the neutral oxygen detected in CENA's energy range (11 eV-3.3 keV) is attributed to have originated from the lunar surface, where it w…
Chandrayaan-1 observations of backscattered solar wind protons from the lunar regolith: Dependence on the solar wind speed
Barabash, Stas; Futaana, Yoshifumi; Wieser, Martin +3 more
We study the backscattering of solar wind protons from the lunar regolith using the Solar Wind Monitor of the Sub-keV Atom Reflecting Analyzer on Chandrayaan-1. Our study focuses on the component of the backscattered particles that leaves the regolith with a positive charge. We find that the fraction of the incident solar wind protons that backsca…
Stellar laboratories. II. New Zn iv and Zn v oscillator strengths and their validation in the hot white dwarfs G191-B2B and RE 0503-289
Rauch, T.; Werner, K.; Kruk, J. W. +1 more
Context. For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. In a recent analysis of the ultraviolet (UV) s…